EP1459034B1 - Method and device for measuring lengths of a workpiece deformed by bending - Google Patents

Abstract

In order to measure lengths L1 or L2 of a bent component (10) in a bending machine (100) such as a bending press, a folding press, a rail bending machine or an automatic bending centre, provided with manipulation systems for handling the workpiece (10) in front of or behind the deformation point, at least one measuring device (9) is disposed either in or on components of the manipulation system, i.e. directly or indirectly on the stop (11) or on the robot, in order to effect measurements directly in the processing area of the bending machine (100).

Description

The invention relates to a method for measuring length on a deformed with a bending machine workpiece, wherein the bending machine can be equipped with handling systems.

The invention further relates to a device for measuring length dimensions on a workpiece deformed by bending with a bending machine and with at least one measuring device for directly or indirectly measuring a length for carrying out the method defined above.

In the production of bent parts, various manufacturing methods are known. The production methods of free bending, embossing bending, pivoting bending and web bending have in common that a bending leg is substantially reshaped, ie bent, by a method step. In all of these bending processes, the process parameters bending angle, inner radius and leg length of the bending mandrel result. The length of a bending mandrel obtained by the forming process is dependent on factors in particular such as bending angle, inner radius, sheet thickness, material parameters - for example strength, modulus of elasticity, hardness.

In order to obtain the most precise dimensions of the bending legs, in particular as accurate leg lengths, usually handling equipment are provided, with the support of the workpiece can be brought into a defined position before forming. Furthermore, additional supply and discharge systems in use, which supply the starting workpiece and can discharge the finished part.

In particular, the length of the bent legs is calculated from the reduction proportion, which must be added to the dimension of the output board of the workpiece. If, due to factors that are not exactly known or unpredictable, such as inner radius, material strength or surface hardness, other shortening components result, a leg length deviating from the nominal dimension results during forming or bending.

So far, it is known to remove the deformed workpiece from the bending machine and then measure the required or desired length later to determine any such errors, while according to DE 30 08 701 A1 Angle measuring devices for press brakes are arranged so that the measurement can be done in the treatment room of the workpiece or even within the bending tool.

The removal of the workpiece from the bending machine for a length measurement means an additional time expenditure between the actual forming of the workpiece and the determination of whether there is an error with respect to a dimension and is to be corrected or not. In addition, the accuracy of the measurement depends on the care of operators.

It is therefore an object to provide a method and a device of the type mentioned, which one or more length measurements performed on workpieces after forming and thereby reduces the loss of time by such a measurement and the accuracy of the measurement of individual skills of operators as far as possible are independent.

To solve this problem, the initially defined method is characterized in that the length measurement on the machined workpiece in the treatment room, where the bending or deformation takes place, is carried out and that as a length measurement, the measure of the bending edge to a free edge of a bending gift, ie the width of the bending gift, or the distance of one or more holes from the bending edge and / or from the free edge of the bending gift or the distance of beads, slots, shapes and / or breakouts of the bending edge or the free edge of the bending gift and / or the Measurement of these deformations themselves or the distance formed by the forming parallel legs, which have one or more Z-shaped or perpendicularly extending intermediate webs, are measured in the treatment space of the workpiece.

This eliminates the need and the time required to remove the workpiece and to measure at a separate location. Furthermore, the measurement can be automated and thereby made independent of individual capabilities of operators. The length dimension to be measured is understood to be, for example, the cross-sectional length of a bending mandrel or even a part thereof. However, it can also be understood as a functional dimension that results from a plurality of bends and bending steps, wherein apart from the example of the clearance between two parallel legs, other functional dimensions can also be understood which can be measured in the same way in the treatment space of the workpiece.

The measurement result can be logged in particular in a computer and / or deviations of a measurement result from a desired value can be used to correct a subsequent bending step and / or bending parts are entered into the control of the bending machine or transmitted automatically.

Thus, not exactly known or unpredictable factors such as inner radius, material strength or surface hardness or other influences that cause a dimension deviating from the nominal dimension or leg length can be determined in the production process and optionally also corrected, without causing any significant delays or even interruptions in operation , The measurement in the treatment room allows a correspondingly fast logging and / or correction of the control of the bending machine.

The length measurement may be performed in a position of the workpiece that results after partial or complete reshaping or bending on the workpiece. The measurement can therefore be carried out when the workpiece is still fixed in the machine, so that virtually no additional time is required for the measuring process.

For example, it is possible that the workpiece is held by the forming tool during the length measurement. Immediately after completion of the forming process, the workpiece is still acted upon by the forming tool and allows in this position a measurement of lengths, in particular the leg length of a bent workpiece, before the workpiece is then released from the forming tool by its provision.

However, a modified embodiment can also provide that the workpiece is placed after deformation or deformation on a lower tool or on this adjacent support of the bending machine and then the length measurement is performed in this position. This can also be avoided, the

To transport workpiece after the bending process to a separate location to measure there. Thus, the essential advantage of the invention is obtained, to require no additional measuring station for the length measurement and, moreover, even with such a procedure, the loss of time is low, since the workpiece is practically at the point at which it was bent. The small additional time required is compensated by the fact that the measurement as such is relatively simple.

The measurement can be carried out in different directions, for example in the plane perpendicular to the bending line, ie perpendicular to a bending leg or in a direction parallel to the bending line level in the profile cross-section of a deformed workpiece. In this case, several lengths can be measured simultaneously, with several lengths can include both one and several legs.

A further embodiment of the invention may be that in the treatment space of the workpiece as a length dimension of the distance formed by the forming parallel legs, which have one or more Z-shaped or perpendicularly extending intermediate webs, is measured. Thus, a length dimension can also be understood to mean a functional dimension that results from a plurality of bends and bending steps, whereby apart from the mentioned example of the clear distance between two parallel legs, other functional dimensions are understood that can be measured in the same way in the treatment space of the workpiece.

An expedient embodiment of the invention may be that the length of the workpiece with at least one, preferably more or in the treatment chamber of the bending machine arranged sensors is measured. By arranged in or at the treatment room sensors for measuring lengths, the inventive method can be particularly useful and easy to perform.

It is expedient if tactile sensors or contactless distance sensors, for example laser distance sensors and / or laser transit time sensors and / or laser interference sensors or contactless contour measurement sensors, in particular laser contour scanners or image processing sensors, are used to measure the length on the workpiece in the bending machine. These sensors are very accurate and can be placed in or on the treatment room of a bending machine in order to perform the length measurement on the machined workpiece in the treatment room.

It may be expedient if the measuring device or the sensor used for measuring is moved out of the treatment chamber before the forming process. This is particularly useful if it is arranged in the treatment room such that it could come to collisions with workpieces during their insertion and in particular their forming.

The device already defined at the outset for measuring length dimensions on a workpiece deformed by bending with a bending machine and with at least one measuring device for direct or indirect measurement of a length may be characterized in that at least one measuring device is used in the workpiece for forming the workpiece Treatment chamber of the bending machine is arranged near the or the forming tools of this bending machine, for measuring the measure of the bending edge to a free edge of a bending gift, ie the width of the bending gift, or the Distance of one or more perforations from the bending edge and / or from the free edge of the bending gift or the distance of beads, slots, shapes and / or breakouts of the bending edge or the free edge of the bending gift and / or the dimension of these deformations themselves or the distance formed by the forming parallel legs which have one or more Z-shaped or perpendicularly extending intermediate webs, in the treatment space of the workpiece.

Thus, the bent workpiece leg can be measured directly in place, without the workpiece or bent part must first be transferred from the bending machine to a measuring station.

A particularly advantageous and expedient embodiment of the invention of its own worthy of protection can consist in that the measuring device on one or more handling devices for handling the workpiece on or in the bending machine and / or on a backgauge of the bending machine for the workpiece and / or the holder the backgauge and / or is arranged on a holder for the workpiece and / or on the machine frame. The invention can therefore be embodied and designed in such a way that, for handling the workpieces in the bending machine, existing handling or stop units which are located in the forming area, ie in the local area of the bending legs, are equipped with corresponding measuring means or measuring devices or sensors and utilized their mobility becomes. Thus, a curved workpiece leg can be measured directly in place, the existing aggregates of the handling devices and stops such as drive, guides, carriers and measuring systems for this measurement on the bent workpiece co-used can be. This is not only inexpensive, but also easy to handle for the user and operator of such a designed bending machine, since he can use and exploit essentially existing machine functions. The measuring device or the measuring devices for measuring one or more lengths on a formed workpiece can thus be adjustable in or on the treatment space of the workpiece and, in particular, be moved out of the area of the forming tool (s). Thus, an adaptation to different dimensions of the workpiece is possible in a simple manner, which can be used for such adjustment movements anyway existing on the machine units.

Sensors, for example measuring probes, ie mechanical measuring devices, or non-contact measuring devices such as triangulation sensors as point or light section sensors, image processing sensors or sensors or scanners operating on the basis of laser beams, can be provided as measuring device or measuring devices. Such measuring devices can also be accommodated well on aggregates belonging to the bending machine and thus in the treatment space of the workpieces.

The measuring device or measuring devices can also be arranged on a robot serving as a handling device, wherein the robot can be associated with the bending machine or this can be assigned with a small distance near the treatment space for the workpiece such that the length dimension in the treatment space of the workpiece of the bending machine is feasible. Just such handling robots, be it directly on the machine arranged and guided handling equipment, be it arranged next to the machine robot, are very often present on such bending machines and can thus by the Carry appropriate measuring devices get an additional function.

Thus, the drives of a stop system and / or handling systems for their axes can be used for direct or indirect positioning of the measuring devices or sensors. Furthermore, possibly existing measuring systems can be used in addition to the evaluation and determination of the leg length on a bent workpiece in these axes.

However, the arrangement of a measuring device in or on the treatment chamber of the workpiece can also be realized by arranging or fixing the measuring device on a cross member of the stop of the machine.

Overall, the combination of individual or more of the features and measures described above, a method and a device, which at the end of the bending process immediately documentation in the sense of quality assurance can be created, which documents the exact interest manufacturing dimensions of the bending part. An additional survey effort for this purpose is eliminated. Further, it is possible to measure the bending legs directly after their formation, so that with increasing number of bends on the same bending part and those bending legs can be measured, which are no longer or only very difficult to measure after a final completion of such a workpiece could.

Furthermore, on the basis of the values determined by these measurements, a database can be set up, which records the shortening parts in relation to the combination of tools used and sheet thickness and / or material and bending angle stores. This can be achieved for such a combination or similar better cut determination for the output board of the workpiece.

Fig.1

eine Seitenansicht einer als Gesenkbiegepresse ausge- bildeten Biegemaschine, in welcher ein Werkstück, an welchem ein Biegeschenkel durch Biegen angebracht wurde, im Behandlungsraum angeordnet ist, so dass die Länge dieses Schenkels, also der Abstand von der Bie- gekante bis zum Rand dieses Biegeschenkels, von einer Messvorrichtung gemessen werden kann, die an dem Hin- teranschlag in geeigneter Weise angeordnet und somit mit dessen Antrieben verstellbar ist,

Fig.2

in vergrößertem Maßstab den Messvorgang gemäß Fig.1,

Fig.3

einen abgewandelten Messvorgang, bei welchem die Länge des gebogenen Schenkels unmittelbar nach der Biegung durchgeführt wird, wenn das Oberwerkzeug das Werkstück noch beaufschlagt,

Fig.4

eine der Fig.1 entsprechende Anordnung, bei welcher die Messvorrichtung an einem als Roboter ausgebilde- ten Handhabungsgerät derart angeordnet ist, dass die entsprechende Längenmessung im Behandlungsraum des Werkstücks durchgeführt werden kann,

Fig.5

eine Seitenansicht eines gebogenen Werkstücks mit ei- nem Biegeschenkel, der gegenüber dem ursprünglichen Werkstück in unterschiedlichen Winkeln dargestellt ist,

Fig.6

ein Werkstück, an welchem ein mehrere Richtungswech- sel aufweisender Biegeschenkel angeformt ist,

Fig.7

in vergrößertem Maßstab ein Werkstück, welches durch zwei entgegengesetzte Biegungen eine etwa Z-förmige Querschnittsform hat,

Fig.8

in schaubildlicher und schematisierter Darstellung die Anordnung eines Messsensors für eine Messung senkrecht zur Biegelinie und zu einem gebogenen Schenkel,

Fig.9

eine der Fig.8 entsprechende Darstellung, bei welcher jedoch eine Messung in einer zur Biegelinie parallelen Ebene im Profilquerschnitt erfolgt, sowie

Fig.10

in schematisierter Darstellung die Anordnung mehrerer Messvorrichtungen, um mehrere Längen auch an ver- schiedenen Schenkeln zu vermessen.

Hereinafter, embodiments of the invention are described in more detail with reference to the drawing. It shows in partly schematized representation:

Fig.1

3 a side view of a bending machine designed as a press bending press, in which a workpiece to which a bending leg has been attached by bending is arranged in the treatment space, so that the length of this leg, ie the distance from the bending edge to the edge of this bending leg, can be measured by a measuring device which is arranged on the rear stop in a suitable manner and thus adjustable with its drives,

Fig.2

on an enlarged scale according to the measuring process Fig.1 .

Figure 3

a modified measuring process, in which the length of the bent leg is performed immediately after the bending when the upper tool is still applied to the workpiece,

Figure 4

one of the Fig.1 corresponding arrangement in which the measuring device is arranged on a handling device designed as a robot such that the corresponding length measurement can be carried out in the treatment space of the workpiece,

Figure 5

a side view of a bent workpiece with a bending leg, which is shown opposite the original workpiece at different angles,

Figure 6

a workpiece on which a bending leg having several directions of change is formed,

Figure 7

on an enlarged scale, a workpiece which has an approximately Z-shaped cross-sectional shape due to two opposite bends,

Figure 8

in a schematic and schematic representation of the arrangement of a measuring sensor for a measurement perpendicular to the bending line and a curved leg,

Figure 9

one of the Figure 8 corresponding representation in which, however, a measurement takes place in a plane parallel to the bending line in the profile cross-section, as well as

Figure 10

a schematic representation of the arrangement of a plurality of measuring devices to measure several lengths on different legs.

A generally designated 100 bending machine, in the illustrated embodiments, a Gesenkbiegepresse, has in a conventional manner a frame 1, a plunger 2, a table 3, an upper tool 4, a lower tool 5 and a generally designated 6 stop system.

A workpiece 10 to be bent is thereby pressed with the upper tool 4 into a notch 5a located in the lower tool 5, which means the plunger 2 and the upper tool 4 thereby perform a movement in the direction of the arrow Y through. This creates the desired bend.

The bending angle can be determined with an angle measuring device 7 and / or the immersion depth of the upper tool 4 can be regulated with it.

It is further provided that on the deformed workpiece 10 in the treatment space where the bending or deformation takes place, a measurement of a length dimension of the bending gift is performed. For this purpose, provision is made in all exemplary embodiments for at least one measuring device 9 to be arranged in the treatment chamber of the bending machine 100 serving for forming the workpiece 10 near the forming tool or tools 4 and 5.

Fig.1 . 2 and 3 represents an embodiment in which the measuring device 9 is arranged on a stop 11 of the stop system 6 of the bending machine 100 for the workpiece 10 directly or indirectly, so possibly also on the holder of the backgauge. Since the abutment 11 is used as a support for the measuring device 9 and these forming sensors, the drives for the movement in the direction of the axis 16 transverse to the bending line, the drives for the movement in the direction of the axis 15, ie for a height adjustment and the movements in the direction of the axis perpendicular to the plane of the stop system 6 are used directly or indirectly as drives for positioning the measuring device 9 and its sensors. In the axes 15, 16, and / or other possibly existing measuring systems can also also be used for evaluation in the measurement of lengths on the workpiece 10. It is also conceivable on the Cross member 8 of the stop system on which the actual stop 11 is adjustable, mounted measuring device. 9

Figure 4 shows an embodiment in which the measuring device 9 is arranged on a trained as a robot 12 handling device for handling the workpiece 10 in particular when feeding or discharging such workpieces 10.

The measuring device 9 or optionally a plurality of such measuring devices 9 for measuring one or more lengths on a formed workpiece 10 is thus adjustable in or on the treatment chamber of the workpiece 10, to which aggregates and components of the bending machine 100 can be used. In this case, the measuring devices 9 can also be moved out of the region of the forming tool (s) or of the workpiece, so that the bending process itself can take place unaffected by such measuring devices 9.

Sensors, for example mechanical measuring probes, or non-contact measuring devices such as triangulation sensors as point or light section sensors, image processing sensors or sensors or scanners based on laser beams can be provided as measuring device 9 or measuring devices.

The measurement result can be logged in a computer and / or deviations of a measuring system from a desired value can be entered for correction in the control in the bending machine 100 in order to be able to correct the quality of the bend in the production process. Since the measurement takes place in the treatment room of the bending machine 1, ie near the tools 4 and 5, practically no additional time is required.

Figure 3 shows the possibility that the length measurement is performed in a position of the workpiece 10, which results after a partial or complete deformation or bending on the workpiece 10. Figure 3 shows that the upper tool 4 has pressed the workpiece 10 in the notch 5a of the lower tool 5 and thereby has generated a bending leg. Whose length L1 can be determined in this position by means of the measuring device 9, which acts on the free edge of the resulting bending mandrel and at the same time "knows" the lowest point of the bend within the notch 5a due to the machine data. The advantage of such a procedure is that the measurement can be carried out practically immediately after the bending process, ie almost without any loss of time, and the workpiece 10 is clamped by the tools 4 and 5.

The measurement of the desired length on the workpiece 10 is thus carried out in this case after the complete, possibly even after a partial deformation, wherein the workpiece 10 is held by means with which it is held during the forming, in the case of a Gesenkbiegepresse with the tools 4 and 5. The workpiece 10 is thus held in this case during the length measurement of the forming tools.

In the Fig.1 . 2 and 4 It is shown that the workpiece 10 after forming or bending on the lower tool 5 or possibly also placed on this adjacent edition of the bending machine 100 and then in this position, the length measurement can be performed. This too can be realized very precisely and means virtually no loss of time.

As a length measurement, the dimension L1 from the bending edge to a free edge of a bending gift, so practically the length of the bending gift, or even the distance of one or more holes from the bending edge and / or from the free edge of the bending gift or the distance of beads , Elongated holes, shapes and / or eruptions from the bending edge or the free edge of the leg and / or the dimension of these deformations themselves are viewed and measured in the treatment space of the workpiece 10 in the manner described above. The show FIGS. 5 to 7 different deformations and limbs, which can be measured with the above-described method and the above-described arrangement in the treatment room after partial deformation and / or after a completed deformation. Figure 7 shows, for example, a deformed workpiece 10, in which the length dimension L2 is the distance of two parallel legs is considered, which together with a gutter form a Z-shaped cross-section. In addition, however, the lengths L1 of the bent legs can optionally be measured successively in the bending machine 100.

Fig.5 and 6 shows further curved workpieces with differently shaped legs, the respective specified lengths L1 can be measured in the treatment chamber of the bending machine 100.

The various exemplary embodiments have in common that handling devices, that is, the stops 11 and / or one or more robots 12, which belong to the bending machine 100 anyway and are arranged near the local area of the bending legs of a workpiece 1, the measuring device 9 can bear directly or indirectly , so that the drives of these units can also be utilized for the adjustment of the measuring devices 9.

In Figure 8 is again shown in principle that the measurement can be carried out with the aid of a measuring device 9 perpendicular to the bending line and perpendicular to the leg of the workpiece 10, as it is also substantially the representation in Fig.1 and 2 equivalent.

Figure 9 on the other hand shows an approximately 90 degrees relative to the workpiece 10 pivoted arrangement of the measuring device 9, which is effective in this case in a plane approximately parallel to the bending line and performs a measurement in the profile cross-section. In this case, the measuring device 9 can also be arranged on the machine frame in these cases.

Figure 10 finally shows that both in the FIGS. 8 and 9 indicated arrangements of measuring devices 9 can be used in combination, which also shows that several lengths can be measured simultaneously, with "several lengths" both a leg and according to Figure 10 can include or mean more legs.

For measuring leg lengths L1 or L2 of a bending part 10 in a bending machine 100, which may be a die bending press, a folding machine, a web bending machine or an automatic bending center and has handling systems for handling the workpiece 10 in front of or behind the forming point, at least one measuring device 9 in or on components of the handling system, ie directly or indirectly on the stop 11 and / or on a robot 12, arranged to perform the measurement directly in the treatment room of the bending machine 100 can.

Claims (15)

1. Method of measuring length on a workpiece (10) deformed using a bending machine (100), wherein the bending machine (100) may be equipped with handling systems, characterised in that the measurement of length is carried out on the machined workpiece in the processing area where the bending or shaping takes place and in that the measurement of length used is the measurement from the bending edge to a free edge of a bent section, i.e. the width of the bent section, or the spacing of one or more perforations from the bending edge and/or from the free edge of the bent section or the spacing of beads, slots, cut-outs and/or openings from the bending edge or the free edge of the bent section and/or the dimensions of these deformations themselves or the spacing of parallel legs formed by the shaping process which have one or more intermediate crosspieces that are Z-shaped or extend at right angles, this measurement being carried out in the processing area for the workpiece.
2. Method according to claim 1, characterised in that the results of the measurement are recorded in a computer, in particular, and/or deviations between the measurements obtained and a desired value are input into the controls of the bending machine (100) for correction purposes.
3. Method according to claim 1 or 2, characterised in that the measurement of length is carried out in a position of the workpiece that is obtained after partial or total reshaping or bending of the workpiece.
4. Method according to one of claims 1 to 3, characterised in that the measurement of the desired length is carried out on the workpiece (10) after total or partial reshaping and the workpiece (10) is held during this time by the means that are also used to hold it during the reshaping.
5. Method according to claim 4, characterised in that the workpiece is held by the reshaping tool during the measurement of length.
6. Method according to claim 1 or 2, characterised in that after the reshaping the workpiece (10) is placed on a lower tool (5) or on a support adjacent thereto on the bending machine (100) and the measurement of length is then carried out in this position.
7. Method according to one of claims 1 to 6, characterised in that the length is measured on the workpiece with at least one, preferably several sensors arranged in or on the processing area of the bending machine.
8. Method according to one of claims 1 to 7, characterised in that in order to measure the length on the workpiece in the bending machine tactile sensors or contactless spacing sensors, for example laser spacing sensors and/or laser run-time sensors and/or laser interference sensors or contactless contour measuring sensors, particularly laser contour scanners or image processing sensors are used.
9. Method according to one of the preceding claims, characterised in that the measuring device (9) or the sensor used for the measurement is moved out of the processing area before the reshaping process.
10. Apparatus for measuring length dimensions on a workpiece (10) deformed by bending, with a bending machine (100) and with at least one measuring device (9) for directly or indirectly measuring a length in order to carry out the method according to one of the preceding claims, characterised in that at least one measuring device (9) is arranged in the processing area of the bending machine (100) used for reshaping the workpiece (10), close to the reshaping tool or tools (4, 5) of this bending machine (100), said device (9) being designed to measure the dimension from the bending edge to a free edge of a bent section, i.e. the width of the bent section, or the spacing of one or more perforations from the bending edge and/or from the free edge of the bent section or the spacing of beads, slots, cut-outs and/or openings from the bending edge or the free edge of the bent section and/or the dimensions of these deformations themselves or the spacing of parallel sections formed by the reshaping process which have one or more intermediate crosspieces that are Z-shaped or extend at right angles, in the processing area for the workpiece (10).
11. Apparatus according to claim 10, characterised in that the measuring device (9) is arranged on one or more handling means for handling the workpiece (10) and/or on a backstop (11) of the bending machine (100) for the workpiece (10) and/or on the holder (8) of the backstop (11) and/or on a holder for the workpiece (10) and/or on the machine frame.
12. Apparatus according to claim 10 or 11, characterised in that the measuring device (9) or the measuring devices (9) are adjustable for measuring one or more lengths on a reshaped workpiece (10) in or on the processing area of the workpiece (10) and in particular can be moved out of the range of the reshaping tool or tools.
13. Apparatus according to one of claims 10 to 12, characterised in that sensors are provided as the measuring device (9) or measuring devices (9), for example measuring sensors or contactless measuring devices such as triangulation sensors in the form of spot detectors or photoelectric sensors, image processing sensors or laser beam-based sensors or scanners.
14. Apparatus according to one of claims 10 to 13, characterised in that the measuring device (9) or devices (9) is or are arranged on a robot (12) serving as a handling device, the robot (12) being connected to the bending machine (100) or being associated therewith at a small spacing adjacent to the processing area for the workpiece (10) such that the measurement of length can be carried out in the processing area for the workpiece (10) in the bending machine (100).
15. Apparatus according to one of claims 10 to 14, characterised in that the measuring apparatus (9) is arranged so as to operate perpendicularly to the bending line and/or in a plane parallel to the bending line.

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